Table 1.

Internalization of bacteria into cultured cell linesa

BacteriumHost cell lineInoculum size (CFU)No. of intracellular bacteria (CFU)b% Internalization
B. pseudomallei
 844J774A.10.78 × 106 (3.85 ± 0.26) × 105 49.36
HeLa0.49 × 106 (0.23 ± 0.04) × 102 0.0047
 UE3J774A.11.27 × 106 (4.57 ± 0.40) × 105 35.98
HeLa2.12 × 106 (3.95 ± 0.77) × 102 0.0186
 UE5J774A.11.11 × 106 (2.32 ± 0.14) × 105 20.92
HeLa1.02 × 106 (0.28 ± 0.09) × 102 0.0027
 UE8J774A.11.02 × 106 (3.73 ± 0.27) × 105 36.57
HeLa1.62 × 106 (1.83 ± 0.46) × 102 0.0113
 UE16J774A.10.82 × 106 (1.68 ± 0.47) × 105 20.49
HeLa1.28 × 106 (1.73 ± 0.38) × 102 0.0135
 UE30J774A.11.01 × 106 (4.25 ± 0.23) × 105 42.08
HeLa1.53 × 106 (1.35 ± 0.17) × 102 0.0088
S. enterica serovar TyphiJ774A.11.23 × 106 (6.45 ± 0.96) × 105 52.44
HeLa2.22 × 106 (1.79 ± 0.06) × 105 8.06
E. coliHB101J774A.12.03 × 106 (0.12 ± 0.01) × 105 0.59
HeLa2.60 × 106 (0.20 ± 0.20) × 101 0.0001
  • a Inocula were added, and the mixtures were incubated for 4 h.

  • b No. of CFU of liberated intracellular bacteria ± standard error of the mean from triplicate wells.